protected override Expression VisitSelect(SelectExpression select)
{
select = (SelectExpression)base.VisitSelect(select);
if (select.Skip != null)
{
Expression expression3;
SelectExpression sel = select.SetSkip(null).SetTake(null);
if (select.IsDistinct || ((select.GroupBy != null) && (select.GroupBy.Count != 0)))
{
sel = sel.AddRedundantSelect(this.language, new TableAlias());
}
QueryType columnType = this.language.TypeSystem.GetColumnType(typeof(int));
sel = sel.AddColumn(new ColumnDeclaration("row__num", new RowNumberExpression(select.OrderBy), columnType)).AddRedundantSelect(this.language, new TableAlias());
sel = sel.RemoveColumn(sel.Columns.Single <ColumnDeclaration>(c => c.Name == "row__num"));
TableAlias alias = ((SelectExpression)sel.From).Alias;
ColumnExpression expression = new ColumnExpression(typeof(int), columnType, alias, "row__num");
if (select.Take != null)
{
expression3 = new BetweenExpression(expression, Expression.Add(select.Skip, Expression.Constant(1)), Expression.Add(select.Skip, select.Take));
}
else
{
expression3 = expression.GreaterThan(select.Skip);
}
if (sel.Where != null)
{
expression3 = sel.Where.And(expression3);
}
select = sel.SetWhere(expression3);
}
return(select);
}
protected BetweenExpression UpdateBetween(BetweenExpression between, Expression expression, Expression lower, Expression upper)
{
if (((expression != between.Expression) || (lower != between.Lower)) || (upper != between.Upper))
{
return(new BetweenExpression(expression, lower, upper));
}
return(between);
}
protected virtual Expression VisitBetween(BetweenExpression between)
{
Expression expression = this.Visit(between.Expression);
Expression lower = this.Visit(between.Lower);
Expression upper = this.Visit(between.Upper);
return(this.UpdateBetween(between, expression, lower, upper));
}
protected override Expression VisitBetween(BetweenExpression between)
{
this.VisitValue(between.Expression);
this.Write(" BETWEEN ");
this.VisitValue(between.Lower);
this.Write(" AND ");
this.VisitValue(between.Upper);
return(between);
}
protected virtual bool CompareBetween(BetweenExpression a, BetweenExpression b)
{
return((this.Compare(a.Expression, b.Expression) && this.Compare(a.Lower, b.Lower)) && this.Compare(a.Upper, b.Upper));
}
